Intellisense is actually Microsoft's trademarked technology AFAIK, so you won't find it anywhere except MS IDEs.
Anyway, arguments you present are like advice to use '' instead of "" for strings, because they're a bit faster. It's not going to make your script execute noticeably faster though, because most time is spend elsewhere.
Same with IDE. What good is instant file opening, when I need to find missing ; or } or) now and then AFTER I have saved the file and reloaded it in browser? In NB you have these (and other) errors highlighted the instant you make them. That's where time is saved.